[ovs-dev] [PATCH] OVN: add selected mac address to MACAM in update_dynamic_addresses

[Lorenzo Bianconi]

Add selected dynamic mac address to MACAM in update_dynamic_addresses
and not just in in ipam_add_port_addresses/ipam_insert_lsp_addresses
since the second approach can produce a duplicated L2 address in a
IPv6-only network if ipv6_prefix is provided after logical port creation.
The issue can be triggered with the following reproducer:

$ovn-nbctl ls-add sw0
$ovn-nbctl lsp-add sw0 sw0-port1
$ovn-nbctl lsp-set-addresses sw0-port1 "dynamic"
$ovn-nbctl lsp-add sw0 sw0-port2
$ovn-nbctl lsp-set-addresses sw0-port2 "dynamic"
$ovs-vsctl add-port br-int p1 -- \
    set Interface p1 external_ids:iface-id=sw0-port1
$ovs-vsctl add-port br-int p2 -- \
    set Interface p2 external_ids:iface-id=sw0-port2
[..]
$ovn-nbctl --wait=sb set Logical-switch sw0 \
    other_config:ipv6_prefix="aef0::"

$ovn-nbctl list logical_switch_port
_uuid               : 1e0e2ed8-20c6-48dc-bfa8-d823e48c9f45
addresses           : [dynamic]
dhcpv4_options      : []
dhcpv6_options      : []
dynamic_addresses   : "0a:00:00:00:00:01 aef0::800:ff:fe00:1"
enabled             : []
external_ids        : {}
name                : "sw0-port1"
options             : {}
parent_name         : []
port_security       : []
tag                 : []
tag_request         : []
type                : ""
up                  : true

_uuid               : cfeab7fb-e20b-41f1-974c-f99e0b5293d7
addresses           : [dynamic]
dhcpv4_options      : []
dhcpv6_options      : []
dynamic_addresses   : "0a:00:00:00:00:01 aef0::800:ff:fe00:1"
enabled             : []
external_ids        : {}
name                : "sw0-port2"
options             : {}
parent_name         : []
port_security       : []
tag                 : []
tag_request         : []
type                : ""
up                  : true

Fixes: c814545b43ac ("OVN: configure L2 address according to the used IP
address")

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
---
 ovn/northd/ovn-northd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c
index 58bef7de5..4580cd705 100644
--- a/ovn/northd/ovn-northd.c
+++ b/ovn/northd/ovn-northd.c
@@ -1341,6 +1341,8 @@ update_dynamic_addresses(struct dynamic_address_update *update)
 
     struct ds new_addr = DS_EMPTY_INITIALIZER;
     ds_put_format(&new_addr, ETH_ADDR_FMT, ETH_ADDR_ARGS(mac));
+    ipam_insert_mac(&mac, true);
+
     if (ip4) {
         ipam_insert_ip(update->od, ntohl(ip4));
         ds_put_format(&new_addr, " "IP_FMT, IP_ARGS(ip4));
-- 
2.19.1